There are some docs ( at 11.04.2001 avaible docs for html, css, php, javascript )
you need to download packages from http://quanta.sourceforge.net
( html.tar.bz2, php.tar.bz2, css.tar.bz2 ) and uncompress them
to $TDEDIR/share/apps/quanta/doc/
or to ~/.trinity/share/apps/quanta/doc/
and restart quanta.